To palletise groups or layers of articles, the articles normally first pass through a grouping station in which the articles initially transported in one or more consecutive rows are moved and/or grouped into palletisable layers. These palletisable layers must be transferred to a suitable loading station capable of carrying out raising movements. The loading station then deposits these layers of articles in a desired place, e.g., a stacking area and a pallet located thereon. The supply and grouping stations may optionally constitute a single unit and/or be directly coupled. The supply and/or grouping station comprise a support surface or level on which the articles are grouped and combined into a layer. The loading station also comprises a support level that may consist of one, two, or more parts. In a support surface of the loading station consisting, e.g., of two parts, the support surface consists of two supports or transfer plates, which are closed when loaded and then subsequently opened during the removal or depositing phase to deposit the layer of articles on a stacking area or pallet. Numerous variants are known to persons skilled in the art, e.g., jalousie gripper heads, etc. Such a palletising method using a prior-art palletising device operates such that, first, articles are grouped into a palletisable layer by means of a grouping device and then transferred from a supply area or supply station to the loading station. To this end, it is necessary for the loading station, e.g., a jalousie gripper head arranged on a hoist element or a robot, to be connected to the supply area so that the layer of articles can be transferred to the loading station. The jalousie gripper head or loading station remains in place until the layer has been completely transferred from the supply station to the loading station. If the layer of articles is completely in the loading station, the loading station positions the layer of articles on a desired transfer point, normally on a pallet provided in a stacking area, by horizontal and vertical movements. Then, the same procedure repeats until the desired number of layers has been placed on the pallet.
DE 10 2008 015 278 A1 discloses a device for loading pallets with piece goods with a piece goods supply station and a transfer device to transfer the group of piece goods from the supply station to a pallet provided on a stacking area and/or a layer of piece goods that has already been transferred to the pallet. EP 1 321 396 A1 discloses another palletising device in which articles are moved laterally and thereby grouped in an unsorted fashion by a horizontal conveyor device before being transferred to a hoisting device in complete layers. The hoisting device or transfer platform serves to compensate for differences in height between the grouping station and the loading station that stacks the layers on top of one another and deposits them on a pallet by opening a retractable floor.
EP 1 908 709 A1 discloses a method and a device for receiving and repositioning bundles. The device has a support for the bundles with an open front side for the insertion of the bundles. A moving slide serves to transfer the bundles in a horizontal receiving direction through the open front side.
Various variants are known from the prior art that are suitable to stack articles assembled in layers on a pallet. However, the prior art methods and devices share the disadvantage that, in order to transfer the layer of articles from a supply station or transfer platform into/onto a loading station, the support surfaces of those elements must be fixed and cannot move vertically and/or horizontally during the transfer of the layer of articles. This can result in time loss in the sense that the beginning of the transfer of the layer of articles can only take place once the loading station or transfer platform has been completely positioned and brought to a stop. As such, it is always necessary to wait until the loading station has reached the stationary supply station before the transfer of the layer of articles can begin. When a transfer platform is used, it is also necessary to wait until the transfer platform has reached the current position of the loading station. Only then can the transfer of the layer of articles begin. Additionally, the respective stations do not execute any vertical and/or movements during the transfer of the layer of articles until the layer of articles has been completely transferred. Either the loading station is moved in to the next respective transfer position only after transferring the layer of articles, or the loading station is already in the next desired transfer position at the time the layer of articles is being transferred.
A primary objective of this invention is to reduce the transfer times between consecutive stations in stationary and/or vertically movable support levels of consecutive stations of a transport system. In this regard, the times between depositing a layer of articles and receiving another layer of articles are to be minimised.
This objective is met by the subject matter of the independent claims substantially by increasing the degrees of freedom of movement of at least one of the consecutive conveyor modules of a transport system. In this way, the transport of layers of articles within a conveyor line can be accelerated such that the movable support surfaces of the modules need not necessarily come to a stop; instead, an oscillating horizontal movement of one support level of one loading station allows the transfer of a layer of articles to begin earlier than had previously been the case. Additionally, a final portion of the transfer movement may be carried out in the area of the loading station whilst it already induces a vertical hoisting movement to place the transferred layer of articles in a deposit area.